Mantaflow. The liquid just doesn't respect the collision object
I agree this seems to be some bug and have seen several posts.   One suggested solution was to use a Surface Thickness equal to the volume of the collision object.   However, Thickness is defined in the docs as an ADDITIONAL dimension beyond the mesh.  When I play with Thickness, it works but has to be a minimum of 0.5 and has a deleterious effect on the liquid boundaries as you'll see here:

I dread to suggestion a solution where a duplicate, hidden collision object that is some 0.5 (what is the translation to units?!!) larger than the visible collision object.
Perhaps another (degenerate) solution is to set &quot;Is Planer&quot; if the collision object is simple or if you break up the collision object into sub-objects. This appears to work.

So until others can be helpful in assisting with a solution (or admission of a bug), then perhaps there is something useful here.